Machine for dovetailing and joining lumber.



B. A. LINDERMAN. MACHINE FOR DUVE'IAILING AND JOINING LUMBER.

APPLIOA'IION TILED MAY 27,1910.

Patented Nov. 22, 1910,

4 BHEBTSSHBET1 B. A. LINDBRMAN.

MACHINE FOR DOVETAILING AND JOINING LUMBER.

APPLICATION FILED MAY 27,1910.

Patented Nov. 22, 1910.

4 SHEETS-SHEET 2.

a Mira/6271 2" jg M 9%. M vzm flfl orrug/b B. A. LINDERMAN.

MACHINE FOR DOVETAILING AND JOINING LUMBER.

APPLIOATION FILED MAY 27,1910.

976, 1 92, Patented NOV. 22, 1910.

4 3HBETSSHEET 3.

B. A. LINDERMAN. MACHINE PO VETAILING AZND APP ATION FILED MAY T JOININGLUMBER Patented N 0v. 22, 1910.

4 SHEETS SHEET 4.

UNITED STATES PATENT OFFICE.

BERT ARTHUR LINDERMAN,

OF MUSKEGON, MICHIGAN.

MACHINE FOR DOVETAILING AND JOINING LUMBER.

To all whom it may concern:

Be it known that I, BERT A. LTNDERMAN, a citizen of the United States,residing in Muskegon, in the county of Muskcgon and State of Michigan,have invented a new and useful Improvement in Machines for Dovetailingand Joining Lumber, of which the following is a specification.

In the uniting of pieces of lumber by means of dovetails formed on thelongitudr nal edges of the lumber, clitliculty has been experienced insupplying the dovetail surfaces with sufficient glue to render the jointas secure and firm as it should be for use in making furniture andinterior house fittings. This inability to retain sufiicient glue in thejoint is due to the fact that if the dovetail surfaces fit closelytogether nearly the entire supply of glue which is applied to thesurfaces at the time they are moved into engagement is forced off ofthem when the engagement takes place, because the uniting movement isnecessarily a longitudinal one and the dovetail surfaces are in closerubbing contact during the whole of it. To increase the quantity of gluewhich may be allowed to remain in the joints so that they may bestrengthened thereby to the degree necessary or desirable, has led tothe making of this invention. I have conceived that if the tongues andgrooves were made to taper slightly in a longitudinal direction from endto end of the stock, that the object sought would be attained, becausein uniting such tapered dovetails the small end of the tongue and thelarge end of the grooves enter into engagement first, but their surfacesdo not come into close or rubbing contact until the uniting movement isnearly complete and the full size of the tongue has arrived at the largeor wide end of the groove. This lack of contact during the initial partof the uniting operation leaves the majority of the glue still adheringto the surfaces and undisturbed, and during the final portion of theuniting operation when the parts are in full contact, there is notsufiicient change of position by either of the dovetailed pieces tocause any serious dislodgment of the glue from its original position.

This invention is adapted to be practiced by the machine illustrated inthe accompanying drawings and described below, and in said drawings,Figure 1 is a side elevation of the machine embodying the presentSpecification of Letters Patent.

Application filed May 27, 1910.

Patented Nov. 22, 1910.

Serial No. 563,688.

invention. Fig. 2 is a horizontal section of the same. Fig. 3 is anenlarged side elevation of a portion of the machine showing the cuttersfor cutting the dovetails on the edge of one of the pieces of board tobe united. Fig. 4 is a partial transverse vertical section of the partsshown in Fig. 3. Fig. 5 is a section on the line 5-5 of Fig. 4-. Figs.(5 and 7 are perspective views of two pieces of lumber provided with thetapering and interfitting dovetails. 8 and 9 are cross sections of thelumber taken in the early stages of the uniting operation; Fig. 10 is anend elevation of the united lumber after the union is completed and Fig.11 is an end elevation of the two pieces of lumber showing the endswhich first engage.

In said drawing 12 represents the frame work of a dovctailing machinebuilt in en] stantial accordance with Letters Patent #827738 granted toA. T. Linderman Au gust 7, 1906, and adapted not only to cut thedovetails in the edge of the stock but also to unite the pieces of stockupon which the dovetails are cut forcing them together with thedovetails in engagement. The machine illustrated is provided with twoparallel endless carriers 18 and let, the carriages 7 of which arelinked together by links 8, and these carriers feed the stock at auniform speed past suitable dovetail cutters. The carriers move inopposite directions so that they are adapted to present the proximateedges of two pieces of lumber to separate cutters at the same time, aswill be under stood, and they are also provided with pressers 15 adaptedto hold the lumber down upon them during the cutting of the dovetailsand also during the uniting operation. These pressers, however, releasethe united lumber as soon as the union is completed allowing it to beejected sidewise by the ejector 16. Mechanism suitable for raising thepressers at the proper time and for operating the ejector at the propertime are shown in said patent. The cutters employed by me are also muchlike those shown in said patent but diifer from them in the provision ofmeans for moving them vertically and transversely to the line of feed ofthe carrier while they are cutting the dovetails, this transversemovement being necessary to give the dovetails the tapering feature. Thecarriers feed the stock at the same speed, and the cutters which aremoved transversely are operated in such movement at the same speed, sothat the dovetail tongues and grooves formed by the cutters are adaptedto interfit as closely as needed for good work. The cutters at one endof the machine are also adapted to form the small end of the tongue ortongues at the advance end of one piece of the stock and the cutters atthe other end of the machine are adapted to form the large end of thegroove or grooves at the advance end of the other piece of stock, sothat as the pieces are fed toward each other after the dovetails areout, such ends first enter into engagement.

I illustrate in detail the cutters 17 and 18 at one end of the machineand operating upon the stock carried to them by carrier 12"). They areadapted to form the doveta1l grooves upon one piece of lumber and aremounted upon arbors 19 and 20, which are inclined in opposite directionsand are supported in suitable bearings 21 and 22 attached to plates 23and 2 1 which are adjustable on center pivots 25 so as to permit changesin the inclination of the arbors. One of the pivots 25 is supported inthe frame 26, and the other pivot 25 is entered in a plate 27 movablysecured in the frame of the machine. In the case of the cutter 17however, I make the supports vertically movable while the cutters areoperating by providing the plate 27 with retaining bars or strips 28attached to the frame of the machine and forming ways in which thatplate may slide vertically, and placing under plate 27 a rotating cam 29mounted on shaft 30 and adapted to give a slow and gradual movement tothe plate 27 by which the cutters 17 will be raised (or lowered)transversely of the line in which the stock is being fed, and thusadapted to gradually widen (on contract) the width of the grooves ortongues as the cut progresses. By these means the tongues or grooveswill be made to taper from one end of the lumber to the other end. Themovable cutter of the drawing cuts the lower side of the grooves, and asit is necessary in machines of the type shown in said Patent #827,738which both out and unite the lumber, that the grooves be wider at theend which is out first, I rotate the cam in the direction indicated inFig. 3. This allows the cutter to fall to its lowest positionpreparatory to operation on a fresh piece of lumber so that the end ofthe groove which is first cut will be the widest part of the groove, andduring the cutting which follows the cam gradually raises the cutter sothat the groove is narrowed as the cutting proceeds.

The cam makes a single revolution during the passage of a single pieceof stock past the cutters, and its speed must therefore be regulated inaccordance with the speed of the carrier. To some extent also its speedshould be regulated in accordance with the length of stock beingoperated upon, as the taper should be continuous and uniform form end toend of the dovetails to allow proper engagement by them. These resultsare easily attained by modifying the cam or changing its speed. Afteroperating upon a piece of stock the cutter 17 is lowered by the cam intoproper position for commencing the cutting upon the next followingpiece. The cutters at the other end of the machine are almost preciselythe same in construction as the cutters 17 and 18, varying therefromonly in being adapted to form the tongues instead of the grooves buttheir construction is well understood and they are not illustrated forthis reason. As in the case of cutters 17 and 18, one of these cuttersfor forming the tongues is adapted to be moved transversely of the lineof feed of the stock while the tongues are being cut, so that thetongues may be tapered correspondingly with the grooves, and for thispurpose a suitable cam adapted to cause such transverse movement, andmaking a single revolution during the passage of a single piece of stockis employed, and given a speed which is regulated in accord ance withthe speed of the carrier, and the length of the stock.

All the cutters used are of a kind well known at this time, and of thoseshown in Figs. 3 and 4 the cutter 17 cuts the lower side of the groovesand the cutter 18 the upper side. I have found that the object of myinvention is accomplished if one only of each pair of cutters is giventhe transverse movement described. It may, however, be provided for bothof each pair if preferred.

In Fig. 6 I show a board 50 upon the edge of which the tapered grooveshave been formed by the cutters 17 and 18 of Figs. 3 and 4, and in Fig.7, I give a like view of another board 51 upon which tapered tonguesadapted to interfit with the grooves of board 50, have been formed, theboard 51 having been cut by the cutters operating on the stock moved bythe carrier 14:.

Immediately after the dovetails have been out in the stock, and beforeit has been carried into engagement, I apply the glue to the dovetailedsurfaces by some suitable means. The device used for applying the glueto the stock moved by carrier 13 consists of a wheel 52, Fig. 3 which isarranged close to the path of the stock so that it bears upon thedovetail surfaces and will be frictionally driven thereby. The wheel issupported upon an inclined axis 53 and one ed e of it is constantlyimmersed in a vat 54: of liquid glue. A similar glue applying device ispreferably though not necessarily used to operate upon the stock out bythe cutters operating on stock moved by carrier 14:, and it is similarlylocated so that it operates on the stock after it has been cut and priorto its engagement with the other stock to which it is to be united. Theglue thus apphed to the dovetail surfaces remains on them during theinitial portion of the uniting operation, as has already been explained,and while the opposing surfaces may come into close bearing contact atthe completion of the operation, it is also true that much of the gluewill then be unable to escape and that the movement of the parts uponone another after they are in full contact will not be suflicient toforce out more than a small percentage of the glue. WVith the taperingdovetails, it will also be remembered that in the uniting operation themovement of the surfaces is not strictly longitudinal, but is alsoslightly sidewise, and consequently is less likely to force the glue outat the end of the stock than where the dovetails are straight. Thesection given at Fig. 8 shows the parts at the start of the unitingoperation, the glue 55 partially filling the open spaces, and Fig. 9shows the parts at a later stage with the parts drawn nearly together.Tn this Fig. 9 it will be seen that the glue is still present though itis now confined closely at all sides in the open spaces which stillremain. At Fig. 10, the parts are shown as having been drawn tightlytogether by the dovetails thus completing the union, and eithercompressing the glue or driving it into the wood so that it hardly showsat the end of the united lumber.

The joint made in the manner set forth and with the glue confinedtherein as de scribed, possesses all the strength needed, and overcomesthe objection noted at the beginning of this specification.

The carrier 13 is supported upon wheels 40 and 41, each having foursides adapted to conform to the length of the carriages 7. The carrier14 laps by carrier 13 sufliciently to permit the two carriers to bringabout complete engagement between the lumber carried by them, and issupported by similar wheels 42 and 43. The inner wheels of both thecarriers have a gearing connection to bevel gears 44 and a shaft 45connects the gears 44 together, so that by applying power to either ofsaid wheels, both carriers may be operated in harmony.

The described transverse movements of the cutters are obtained from thecarriers by belting 46, driving the pinion 47 and act-uating the shaft30 by the intervening gears 48 and 49. Similar means are employed foractuating both cams 29.

I claim 1. The lumber joining machine, embracing means for cuttinglongitudinal tapering dovetails on the proximate edges of two oppositelymoving pieces of lumber, means for applying glue to said dovetails, andmeans for feeding said lumber longitudinally past the cutting means intoengagement with each other.

2. The lumber joining machine wherein are combined oppositely moving andlapping carriers, cutters for forming interfitting longitudinallytapering tongues and grooves on the proximate edges of two pieces oflumber mounted on said carriers, said tongues and grooves being formedwith advance ends adapted to engage and means for applying lue to saidtongues and grooves.

3. The lumber joining machine wherein are combined oppositely moving andlapping carriers, cutters for forming tapering dovetail grooves on theedges of a piece of lumber mounted on one of said carriers, with thewide end of the grooves at the advance end, and cutters for formingtapering dovetail tongues on the edge of another piece of lumber mountedon the other carrier with the small end of the tongues at the advanceend, and means for applying glue to said dovetails.

4. The lumber oining machine having means for feeding two pieces oflumber in opposite directions, cutters for forming dovetails on theproximate edges of said pieces, said cutters being also movabletransversely to the line of the feed, and means for applying glue tosaid dovetails, said feeding means being also adapted to carry saidpieces into engagement with each other.

5. The lumber joining machine having two sets of cutters for forminginterfitting dovetails 011 the surfaces of two pieces of lumber, meansfor giving the cutters movement transverse of the line of the feed whilecutting the dovetails, means for applying glue to the dovetails, andmeans for feeding said pieces past the cutters and into engagement witheach other.

BERT ARTHUR LINDERMAN.

WVitnesses:

WALTER PALMER MARSHALL, MYRTLE VVURTZLER.

